• Geomechanics and Engineering
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• 제32권4호
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• pp.375-385
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• 2023

There are many joint fissures distributed in the engineering rock mass. In the process of geological history, the underground rock mass undergoes strong geological processes, and undergoes complex geological processes such as fracture breeding, expansion, recementation, and re-expansion. In this paper, the damage-stick-slip process (DSSP), an analysis model used for rock mass failure slip, was established to examine the master control and time-dependent mechanical properties of the new and primary fractures of a multi-fractured rock mass under the action of stress loading. The experimental system for the recemented multi-fractured rock mass was developed to validate the above theory. First, a rock mass failure test was conducted. Then, the failure stress state was kept constant, and the fractured rock mass was grouted and cemented. A secondary loading was applied until the grouted mass reached the intended strength to investigate the bearing capacity of the recemented multi-fractured rock mass, and an acoustic emission (AE) system was used to monitor AE events and the update of damage energy. The results show that the initial fracture angle and direction had a significant effect on the re-failure process of the cement rock mass; Compared with the monitoring results of the acoustic emission (AE) measurements, the master control surface, key blocks and other control factors in the multi-fractured rock mass were obtained; The triangular shaped block in rock mass plays an important role in the stress and displacement change of multi-fracture rock mass and the long fissure and the fractures with close fracture tip are easier to activate, and the position where the longer fractures intersect with the smaller fractures is easier to generate new fractures. The results are of great significance to a multi-block structure, which affects the safety of underground coal mining.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.266-267
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• 2021

최근 코로나 19팬데믹은 감염병 차원의 재난이 아닌 복합재난의 전형으로 전통적인 재난대응 관리방식으로는 대응하기가 어려워졌다. 이에 코로나 블루와 같은 심리적 스트레스와 트라우마를 경험하는 것이 새로운 사회문제로 부상하였다. 따라서 심리적 재난 및 위기를 선제적으로 예측하고 효과적으로 대응함에 있어 전통적 서비스에 ICT기술을 활용한 비대면 재난심리지원의 필요성과 방향에 대해 논한다.

• 한국재난정보학회 논문집
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• 제15권2호
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• pp.259-267
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• 2019

연구목적: 본 논문에서 접착제로 접착된 원통형 랩 접합부는 피착체가 탄성이고, 접착제가 선형 점탄성이라고 가정한다. 연구방법: 피착제의 응력 분포는 유한요소법을 사용하며, 4개의 아이소파라메터 점탄성 고체 접착제를 통해 피착제에 대한 해석결과를 검증한다. 연구결과: 접착층에서의 시간에 대한 응력분포와 피착제의 두께와 탄성율이 규격화에 미치는 응력의 영향을 검토한다. 결론: 본 연구는 접착제층의 점탄성을 고려한 랩접착된 원통체의 접착제층의 응력분포에 대해서 4요소 탄성체 모델을 사용하여 수치해석을 하였다.

• 한국재난정보학회 논문집
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• 제19권4호
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• pp.788-805
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• 2023

연구목적: 본 연구는 우기의 상습 침수로 인해 지속적으로 재난 스트레스를 경험한 방글라데시 남부 거주민들을 대상으로 (사)한국 해비타트의 재난위기경감 개입이 수혜자들의 정신건강 및 삶의 만족도에 어떠한 영향을 미치는지 검증하고자 하였다. 연구방법: 이를 위해 개입대상지역에 거주하는 138명의 성인 남녀를 대상으로 2020년 8월 사전조사 및 2021년 11월 사후조사를 수행하였다. 중재적 개입은 개별 점진주택 제공, 공용인프라시설 개보수, 재난대응훈련을 통한 역량개발로 구성되었다. 자료분석방법으로는 사전-사후의 변화에 대한 대응표본 t-test와 처치집단 간의 차이를 밝히기 위한 일원분산분석을 사용하였다. 연구결과:분석결과, 개입 후 거주민의 우울, 불안, 신체화 및 삶의 질 모두에서 유의한 향상이 나타났으며, 개입 처치에 따른 정신건강 수준에서도 유의한 차이를 보였다. 구체적으로 재난대응훈련과 대비하여 개별 점진주택 제공과 공용인프라시설 개보수에서 상대적으로 높은 효과가 확인되었다. 결론:이러한 결과는 (사)한국 해비타트의 재난위기경감 개입이 재난 피해자의 정신건강 회복에 미치는 긍정적 역할을 입증하였으며, 이를 바탕으로 재난취약 개도국 대상의 위험 지역에서 적용할 수 있는 실제적 개입방식을 제안하였다.

• Geomechanics and Engineering
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• 제32권3호
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• pp.245-254
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• 2023

Through qualitative analysis and quantitative analysis, the contradictory conclusions about the stability of the settled goaf with two-layer coal seams subject to building load were obtained. Therefore, it is necessary to combine the additional stress method and numerical simulation to further analyze the foundation stability. Through borehole analysis and empirical formula analogy, the height of water-conducting fracture zone in No.4 coal and No.9 coal were obtained, providing the calculation range of water-conducting fracture zone for numerical simulation. To ensure the accuracy of the elastic modulus of broken gangue, the stress-strain curve were obtained by broken gangue compression test in dried state of No.4 coal seam and in soaking state of No.9 coal seam. To ensure the rationality of the numerical simulation results, the actual measured subsidence data were retrieved by numerical simulation. FISH language was used to analyze the maximum building load on the surface and determine the influence depth of building load on the foundation. The critical building load was 0.16 MPa of No.4 settled goaf and was 1.6 MPa of No.9 settled goaf. The additional stress affected the water-conducting fracture zone obviously, resulted in the subsidence of water-conducting fracture zone was greater than that of bending subsidence zone. In this paper, the additional stress method was analyzed by numerical simulation method, which can provide a new analysis method for the treatment and utilization of the settled goaf.

• 스트레스연구
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• 제25권2호
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• pp.105-119
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• 2017

재난 대응의 첫 단계는 준비이며, 교육과 훈련은 준비의 중요한 요소로 간주된다. 본 연구의 목적은 자원봉사자 교육 프로그램을 개발하기 위해 재난 이후의 봉사 경험을 탐색함으로써 자원봉사자들의 요구를 파악하는 것이다. 본 연구에서는 안산 지역에서 세월호 사건이후 약 1년간 자원봉사에 참여한 경험이 있는 일반인 11명(팀장급 6, 팀원 5)을 대상으로 개인 수준, 팀 내 수준 및 팀/조직 간 수준에서 자원봉사 경험, 훈련 욕구와 필요한 역량에 대한 포커스 그룹 인터뷰를 실시하였다. 그 결과, 자원봉사자들의 자기 및 동료 케어와 전문적 교육 요구의 주제가 보고되었다. 연구의 한계점에도 불구하고 자원봉사자의 역량 개발 및 정신 건강 욕구를 확인하였으며, 향후 연구 방향을 제시하였다는 점에서 의의가 있다.

• Geomechanics and Engineering
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• 제38권3호
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• pp.215-229
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• 2024

Because of the various patterns of deep-water inrush and complicated mechanisms, accurately predicting mine water inflows is always a difficult problem for coal mine geologists. In study presented in this paper, the water inrush channels were divided into four basic water diversion structures: aquifer, rock fracture zone, fracture zone and goaf. The fluid flow characteristics in each water-conducting structure were investigated by laboratory tests, and multistructure and multisystem coupling flow analysis models of different water-conducting structures were established to describe the entire water inrush process. Based on the research of the water inrush flow paths, the analysis model of different water inrush space structures was established and applied to the prediction of mine water inrush inflow. The results prove that the conduction sequence of different water-conducting structures and the changing rule of permeability caused by stress changes before and after the peak have important influences on the characteristics of mine water-gushing. Influenced by the differences in geological structure and combined with rock mass RQD and fault conductivity characteristics and other mine exploration data, the prediction of mine water inflow can be realized accurately. Taking the water transmitting path in the multistructure as the research object of water inrush, breaking through the limitation of traditional stratigraphic structure division, the prediction of water inflow and the estimation of potentially flooded area was realized, and water bursting intensity was predicted. It is of great significance in making reasonable emergency plans.

• Steel and Composite Structures
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• 제44권5호
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• pp.619-632
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• 2022

There are numerous structural details (Longitudinal beam, web plate, U-ribs and I-ribs) in the top and bottom plates of steel box girders, which have significant influences on the longitudinal stress (normal stress) distribution. Clarifying the influence of these structural details on the normal stress distribution is important. In this paper, the ultra-wide steel box girder with large cantilevers of the Jinhai Bridge in China, which is the widest cable-stayed bridge in the world, has been analyzed. A 1:4.5 scale laboratory model of the steel box girder has been manufactured, and the influence of structural details on the normal stress distribution in the top and bottom plates for four different load cases has been analyzed in detail. Furthermore, a three-dimensional finite element model has been established to further investigate the influence regularity of structural details on the normal stress. The experimental and finite element analysis (FEA) results have shown that different structural details of the top and bottom plates have varying effects on the normal stress distribution. Notably, the U-ribs and I-ribs of the top and bottom plates introduce periodicity to the normal stress distribution. The period of the influence of U-ribs on the normal stress distribution is the sum of the single U-rib width and the U-rib spacing, and that of the influence of I-ribs on the normal stress distribution is equal to the spacing of the I-ribs. Furthermore, the same structural details but located at different positions, will have a different effect on the normal stress distribution.

• 지질공학
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• 제24권1호
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• pp.81-89
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• 2014

국내 터널현장에서는 일차 지보재의 안정성 및 이차라이닝의 두께와 시공 시기 등을 결정하기 위하여 숏크리트에서 응력 측정을 수행하고 있다. 본 연구에서는 국내 여러 지역의 터널 현장에서 수행된 숏크리트 응력 측정 사례의 분석을 통하여 숏크리트 계측 현황 및 숏크리트 안정성 평가 기준의 문제점을 제시하였다. 또한 개선된 숏크리트 응력 계측 방법을 시공 중인 터널현장에 적용한 사례를 제시하였다. 현재와 같이 숏크리트의 안정성 평가를 측정응력의 절대적 크기를 통하여 수행하기 위해서는 숏크리트 응력 측정의 신뢰성 향상이 필요하다.

• Geomechanics and Engineering
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• 제22권5호
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• pp.461-473
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• 2020

Natural rock mass contains defects of different shapes, usually filled with inclusions such as clay or gravel. The presence of inclusions affects the failure characteristics and mechanical properties of rock mass. In this study, the strength and failure characteristics of rock with inclusions were studied using the particle flow code under uniaxial compression. The results show that the presence of inclusions not only improves the mechanical properties of rock with defects but also increases the bearing capacity of rock. Circular inclusion has the most obvious effect on improving model strength. The inclusions affect the stress distribution, development of initial crack, change in crack propagation characteristics, and failure mode of rock. In defect models, concentration area of the maximum tensile stress is generated at the top and bottom of defect, and the maximum compressive stress is distributed on the left and right sides of defect. In filled models, the tensile stress and compressive stress are uniformly distributed. Failing mode of defect models is mainly tensile failure, while that of filled models is mainly shear failure.